包装用捆带断带原因分析

１前言捆带，俗称“铁腰子”，在冷轧厂的各生产工序钢卷打捆和成品包装中都离不开它。如果在各生产工序中打捆的捆带断带，不仅影响生产作业率和产品的成材率，同时也会影响产品的质量。如果成品包装的捆带断带，则要影响产品的声誉和市场竞争力，甚至还要影响企业的经济...     

捆带产品和工艺开发

捆带产品和工艺开发宝钢捆带公司生产的各种规格的优质捆带材料，主要用于钢材、建材、棉花、给草、轻纺等行业的打捆包装。主要生产设备由热处理线、纵切涂漆线和锁扣生产线组成，系从原西德Ｐ．Ｗ．Ｌｅｎｚｅｎ厂成套引进，是宝钢２０３０ｍｍ冷轧设备的组成单元，于１...     

热轧钢卷捆带断裂机理及其防治技术

针对热轧钢卷周向捆带出现的断裂问题,从捆带断裂机理分析入手,在分析了捆带断裂强度条件的基础上,建立了一套捆带断裂预报模型。首次提出了利用钢卷捆带断裂系数来表示热轧钢卷发生捆带断裂的概率的方法,从统计学的角度给出了钢卷捆带断裂的判断条件和捆带分档使用原则,开发出了相应的捆带断裂的防治技术并编制出了一套完整的捆带分档使用软件。将其推广应用到生产实践,取得了良好的使用效果,有效降低了热轧钢卷周向捆带断裂的发生率,给企业创造了较大的经济效益,具有进一步推广应用的价值。     

钢卷包装周向捆带受力分析及应用

通过材料力学、弹性力学和塑性力学等有关的工程固体力学进行分析计算得出对包装用捆带的捆扎力受力分析。从工程应用的角度上,通过对钢卷的周向捆带的受力分析,形成适用于钢卷包装用的基础性理论和计算公式,为提高钢卷包装质量提供理论依据。     

提高鞍钢包装用捆带质量的研究

将鞍钢附企冷轧金属制品厂生产的包装用捆带的各项技术条件与宝钢生产的捆带进行对比,从中找出鞍钢的捆带自身的质量问题及产生原因,并根据鞍钢目前资金短缺的具体情况,对鞍钢现有的包装用捆带生产机组的部分工艺和设备提出了较为可行的改进措施。     

钢卷捆带自动拆除装置

Sundwig研制了一种新型钢卷捆带自动拆除装置。它装在光亮退火机组的进口区,共设两台拆卷机拆除捆带。这套装置可不借助人力实行自动操作。 紧凑的机头允许横向和旋转运动,并可自动测定卷边和捆带的位置。捆带用剪机切断,并卷成     

基于酸轧入口钢卷捆带机器人自动拆捆系统开发与应用

由人工承担冷轧酸轧机组入口处钢卷拆除捆带工作,存在劳动强度较大、工作效率低以及危害风险较高等难题。在满足酸轧机组入口处开卷工艺的前提下,采用系统集成技术研发了一款机器人自动拆捆系统代替人工从事钢卷拆剪捆带工作,整套系统设计合理、工作稳定可靠,所设计的与机器人相匹配的拆剪捆带机构、捆带回收装置以及安全装置能够较好的适应该机器人自动拆捆系统,实现了对钢卷的自动拆剪和捆带的回收,降低了工人的劳动强度、提高了工作效率以及降低了工人的危害风险。该机器人自动拆捆系统可广泛应用于板卷深加工开卷前拆捆带工序上。     

浅析自动打捆机夹紧剪切单元改进

目前邯宝冷轧厂镀锌线采用先进的连续热镀锌工艺,在生产线出口有自动打捆机,保证钢卷打捆后直接运输到包装线进行包装,此设计工艺省时省力省人工,具有很大的优越性,但是使用的捆带硬度偏高,同时打捆机夹紧剪切单元的结构设计不能满足强度上的使用要求,自动打捆机在对成品镀锌钢卷的打捆过程中,多次出现夹紧剪切单元的剪刃崩裂、夹钳断裂以及移动剪刃动作不到位剪切不断捆带故障,导致打捆机不能自动打捆。基于此通过分析研究,对打捆机进行了优化改进,有效防止剪切单元问题发生。     

打捆机捆丝去除氧化皮装置设计

目前国内钢厂一些打捆机用的捆丝由于存在氧化皮问题,不论是国产打捆机还是进口打捆机在打捆时,氧化皮会由于抽丝、扭结等受力而脱落至送丝槽等部位,故打捆机常常产生跑丝,卡阻等问题。为了解决此问题,设计并制作了一种去除打捆机捆丝氧化皮装置,并通过对不同直径的捆丝以及不同压下量的分组实验,得出压下量以及捆丝直径的变化对捆丝去氧化皮效果的影响。该装置具有结构简单紧凑,占地面积小,价格低廉,易于操作和维护,能适应各种恶劣的工作环境等特点。具有一定的经济价值和现实意义。     

石横特钢提高热轧带肋钢筋收集质量的措施

为适应出口标准要求,石横特钢对热轧带肋钢筋打捆包装生产线进行改造。通过增加打捆装置、喷漆枪代替手工毛刷刷漆、规范标牌悬挂等措施,收集包装质量明显提高,作业率提高10%~15%。     

Nonlaminated FRP Strap Elements for Reinforced Concrete, Timber, and Masonry Applications

Advances in material technology allow for the exploration of new structural forms and systems. In recent years, fiber-reinforced polymers (FRPs) have emerged as candidate materials for civil engineering applications, and the use of FRPs in construction has been an area of growing interest. Unidirectional high-strength FRPs are well-suited for use as tensioning elements, but anchorage details present a challenge. An alternative is to self-anchor the FRP tensioning element by winding thin layers of material around supports and then laminating all the layers together (a laminated strap) or by securing only the outermost layer to form a closed outer loop while the inner layers remain nonlaminated (a nonlaminated strap). Nonlaminated FRP straps have been found to have higher efficiencies than equivalent laminated straps, which is advantageous in high-tension applications. The suitability of nonlaminated FRP straps for use as unbonded tension elements provides scope for use in new construction and for the strengthening of existing structures. A review of nonlaminated carbon FRP strap system properties and applications in the context of reinforced concrete, timber, and masonry structures is presented.     

冷轧钢卷最大约束反力分析

根据冷轧钢卷外周钢带的边界约束条件,采用三维应力和微积分分析的方法,得出钢卷最大约束反力的计算公式;最大约束反力与钢卷厚度的平方、宽度和抗拉强度成正比、与钢卷外径成反比。在一般冷轧机组设备生产能力下,钢卷最大约束反力随钢卷材料抗拉强度的增加而递增。在给定的生产能力下,通过计算出钢卷最大约束反力的极限值,为钢卷打捆工艺制定和捆带材质选择提供依据,以有效避免钢卷内捆带失效的情况发生。     

Efficient CFRP Strap Configurations for the Shear Strengthening of Reinforced Concrete T-Beams

A prestressed carbon fiber-reinforced polymer (CFRP) strap retrofitting system has been found to significantly enhance the shear capacity of existing reinforced concrete beams. In previous studies, the CFRP straps were supported on metal pads placed on the top and bottom of a beam necessitating top surface access. The goal of the current work was to develop a system where the straps were installed from underneath a slab without compromising the strengthening efficiency. A series of T-beam experiments was conducted where the CFRP straps were inserted through holes that were drilled from below the flange, thereby avoiding the need for access to the top surface. The depth of penetration of the CFRP straps into the compression flange, the concrete strength, the CFRP strap spacing, the presence of holes in the compression flange, and the size of the loading pads were all found to affect the shear performance. Using the most successful installation technique, the resulting CFRP strengthened beam failed at a load that was approximately 50% higher than that of an unretrofitted control beam.     

热轧卷取机卷筒胀缩机构磨损浅析

对热轧卷取机卷筒胀缩原理、磨损情况进行分析,利用专用工器具测量并计算各部件磨损量,以准确把握卷筒胀缩状态,为卷筒的更换提供数据支持。     

Modeling of an Unbonded CFRP Strap Shear Retrofitting System for Reinforced Concrete Beams

A retrofitting technique has been developed that uses carbon fiber-reinforced polymer (CFRP) straps to increase the shear capacity of reinforced concrete beams. The vertical straps are not bonded to the beam but are instead anchored against the beam, which makes this technique potentially more effective than bonded FRP retrofitting techniques. However, it also means that models for bonded FRPs are not appropriate for use with the straps. Instead, a model based on a shear friction approach has been developed where the strain in the straps is calculated based on a term that accounts for the effects of prestress and additional strain in the strap due to shear crack opening. The model can either consider the shear reinforcement to be smeared along the length of the beam or discrete elements. The “smeared” model was checked against an experimental database consisting of rectangular, T-, and deep beams, both in terms of predicted capacity and predicted strain in the straps. Overall the smeared model predicted the capacity of the specimens and, with some adjustments, the strains quite accurately. There were, however, cases when it was more appropriate to use the “discrete” model such as when the transverse reinforcement ratio was low or when the transverse reinforcement spacing was high. Further experimental data are required to fully validate the models and to determine appropriate limits on the use of the smeared model and the discrete model. However, the initial results are promising.     

Biomechanical effects of functional knee bracing. Practical implications

Bracing of the anterior cruciate-deficient knee remains controversial. Close review of published data has revealed enough common observations about braces that strong suggestive information can be utilised for clinical purposes until more concrete data are provided. Brace function can vary with design. The primary differences noted are between the shell-type and strap-type braces. Shell braces tend to provide more stability to the knee than do the strap braces. Proper hinge placement, rather than type, affects pistoning and overall performance of the brace. Custom braces provide a better fit than off-the-shelf devices, but they can feel more restrictive, especially the shell braces. Static bench-testing data have shown that these braces provide little stability against anterior tibial translation at forces comparable to athletic play. Yet kinematic and force plate data suggest that they may produce some mechanical constraining effect to the entire lower extremity instead of just the knee joint. The literature still supports the philosophy that functional bracing should be considered as part of a comprehensive rehabilitation programme for an anterior cruciate-deficient athlete with significant functional deficits.     

德兴铜矿富家坞运输机张紧系统改造

张紧装置是运输机系统的重要组成部分,因设计理念和现场环境等多方面原因,德兴铜矿富家坞张紧装置出现了多次故障停机,严重影响了生产,针对实际情况,结合运输机系统特点,采用新的液压张紧装置,该张紧装置的应用特点、结构组成、液压系统工作原理及PLC控制原理做了具体介绍。经实践证明,该液压张紧装置在生产实践当中运行稳定、可靠。     

Vibrational Tension Measurement of External Tendons in Segmental Posttensioned Bridges

A rapid and economical vibrational tension measurement method is presented to detect distress in external tendons used in segmental posttensioned bridges. This method provides a complementary technique to traditional inspection methods currently employed in the field. The natural frequency and overtones produced by an impact excitation are measured and used to determine the tendon segment’s tension and flexural stiffness using a differential equation describing a stiff string with clamped-clamped boundary conditions. The flexural stiffness is not negligible in tendons of this type causing the vibration modes to be inharmonically related. This method provides consistent (typically within 1%) and reasonably accurate (typically within 10%) estimates of tendon tension. Accuracy can be improved by lessening uncertainty in input constants such as the tendon mass and tendon length. Application examples from several in-service bridges have shown that detection of corrosion damage, improper tensioning, and force distribution effects from friction at deviation blocks can be detected.